Restore portrait.py's abilities to rotate windows.

Restore portrait.py's abilities to rotate windows.
Disable animations in configuration window.
Set the size request of about dialog to 800x800 to support portrait mode.
Pass the parent to about dialog and set it as needed to support postrait mode.
Add credits for postrait.py too.
Clear animation cache when animations are disabled.
Add code for portrait mode support: Disabled for now since it isn't reliable.